The invention provides a method for preparing a SiC whisker-reinforced composite material. A matrix material such as a metal, an alloy or a plastic is introduced into a fibrous base consisting of a SiC whisker sponge-like cake. The resultant structure is compressed into a desired shape as needed. The fibrous base is prepared by heating a mixture of silica gel or ashed rice hulls with a furnace carbon black and an additional amount of NaCl as a space forming agent for forming spaces conducive to whisker growth.